Beneficial Insects for Garden Pest Control

Attracting beneficial insects to your edible garden is the easiest way to keep garden pests in check. You'll be glad to know that it's also the most low-maintenance and economical way for pest control. To attract the beneficial predators to the garden, we'll have to provide food for both the adults and the young insects, in addition to habitat.

What is a garden pest?

Ladybug larvae eating the gray aphids on asparagus

A garden pest is a prey insect, and like all prey, it multiplies quickly and without regard for food source or habitat limits [not talking about humans this time!]. It will stick around as long as there is food and there aren't any predators. Aphids, flea beetles, cabbage worms, squash bugs, cucumber beetles, and tomato hornworms are a few of the most common pests. I've written about pests before, and you can read about my battle with squash bugs and my discovery of ladybugs in the asparagus.

What is a beneficial insect?
A beneficial insect is a predator; a natural enemy to the pests. As in the rest of nature, there are always fewer predators, and they are usually solitary creatures. They do the job of pest control for us and save us time and frustration in the garden.  Some examples include beetles, flies, ladybugs, spiders, and wasps. Here is a slideshow of beneficial insects that I've seen around our homestead and was able to capture in a photo.



Why do I get garden pests?
Are you growing delicious fruits and vegetables to enrich your family's diet? Garden pests are not much different than us - they seek out delicious food. They are opportunists, and their main objective is to survive and procreate. We can't fault them for having a similar desire to eat and live well. Your garden is providing them with a silver platter feast!  Rather than hating the pests, we have an opportunity to learn about nature in the place where we live.

Soil Health
Plants have natural defenses to protect themselves from pests. After all, the plants themselves are also trying to survive and procreate. And like humans, a plant's defenses are only as good as its health. It needs vitamins and minerals to stay strong. Natural gardening is great for those who like to play detective and solve mysteries. How healthy is your soil? Are there specific nutrients that the plant you're growing really needs extra of, and isn't getting from the soil? A soil test can help answer that question. If you're not sure, just add compost. Add more than you think you need. Homemade compost, mushroom compost, worm castings, or composted animal manure are all great choices.

Vegetable Plant Selection
Maybe your plants were disadvantaged from the start. Did you choose the largest seedlings at the nursery? This is the most common mistake. Ideally your baby seedlings would have no more than 2-3 sets of leaves on it prior to placement in a permanent home, whether in ground or container. Bigger is not always better.

Once we've thought about soil health and plant selection, we're ready to think about attracting the beneficial insects. All of these considerations are connected in the natural garden.

Food for Beneficial Insects

Swiss chard bordered with sweet alyssum and backed by echinacea

Beneficial insects are predators, meaning they are carnivorous and will consider those garden pests as their silver platter! Sometimes only the young insects are the carnivores, while the vegetarian adults prefer nectar. We need to make sure that both the adults and young ones are well-fed. Grow herbs and flowers near and in your vegetable garden that will attract the good guy adults searching for nectar.  My gardens are almost always bordered with sweet alyssum or calendula. There are many long lists of host plants (specific plants required by specific species) to grow for the beneficial insects, but you can't go wrong with parsley, dill, fennel, coriander, and sweet clover. You'll have to let them flower. Read about the swallowtail caterpillars I found on my parsley plant!

Habitat
The golden rule: There must be an undisturbed area somewhere near your garden. It can be a cultivated area of perennials that perhaps you only weed once a year to keep it manageable, but it must be an area you're not micromanaging and tromping through constantly. This is the only way the good guys are going to stick around. They prefer a quiet street away from chaos!

Prevention is the best medicine, and it will save you time and money in the long run. Don't buy costly products again, and don't wait until you've found a pest outbreak and then try to provide food and habitat for the beneficial insects. It will be too late. Start your garden season off with healthy soil and plants, and nectar and undisturbed habitat for the predators.